TECHNICAL FIELD
[0001] The present invention relates to an abnormality factor determination apparatus, a
degradation determination apparatus, a computer program, a degradation determining
method, and an abnormality factor determining method.
BACKGROUND ART
[0002] An energy storage device has been widely used in an uninterruptible power supply,
a DC or AC power supply included in a stabilized power supply, and the like. In addition,
the use of energy storage devices in large-scale systems that store renewable energy
or electric power generated by existing power generating systems is expanding.
[0003] An energy storage module has a configuration in which energy storage cells are connected
in series. It is known that degradation of an energy storage cell progresses by repeating
charge and discharge. Patent Document 1 discloses a technique of detecting a state
of charge (SOC) of a secondary battery for a vehicle by inputting a detected value
of a state quantity of the secondary battery to a learned neural network unit.
PRIOR ART DOCUMENT
PATENT DOCUMENT
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0005] It is considered that charge-discharge behavior and a rate of degradation of an energy
storage device installed in a mobile body or facility are different depending on environmental
states such as installation conditions of the energy storage device and ambient temperature.
When the state quantity of the energy storage device is input into the learned neural
network unit and whether the energy storage device has been degraded earlier than
assumed is determined, it is not possible to distinguish whether the energy storage
device has actually been degraded or has been erroneously determined to be degraded
despite being normal due to an environmental difference.
[0006] It is an object of the present invention to provide an abnormality factor determination
apparatus, a degradation determination apparatus, a computer program, an abnormality
factor determining method, and a degradation determining method, which determine an
abnormality factor relating to an energy storage system including a plurality of energy
storage devices.
MEANS FOR SOLVING THE PROBLEMS
[0007] An abnormality factor determination apparatus, which determines presence or absence
of an abnormality factor relating to an energy storage system including a plurality
of energy storage devices, is provided with: a measured value acquisition unit that
acquires measured values including electric values and temperature values of the plurality
of energy storage devices; a predicted value acquisition unit that acquires predicted
values including electric values and temperature values of the plurality of energy
storage devices; and a determination unit that determines presence or absence of an
abnormality factor relating to the energy storage system based on each of the measured
values acquired by the measured value acquisition unit and each of the predicted values
acquired by the predicted value acquisition unit.
[0008] A computer program, which causes a computer to determine presence or absence of an
abnormality factor relating to an energy storage system including a plurality of energy
storage devices, causes the computer to perform processing of acquiring measured values
that include electric values and temperature values of the plurality of energy storage
devices, processing of acquiring predicted values that include electric values and
temperature values of the plurality of energy storage devices, and processing of determining
presence or absence of an abnormality factor relating to the energy storage system
based on each of the acquired measured values and the acquired predicted values.
[0009] An abnormality factor determining method, which determines presence or absence of
an abnormality factor relating to an energy storage system including a plurality of
energy storage devices, includes: acquiring measured values that include electric
values and temperature values of the plurality of energy storage devices; acquiring
predicted values that include electric values and temperature values of the plurality
of energy storage devices; and determining presence or absence of an abnormality factor
relating to the energy storage system based on each of the acquired measured values
and the acquired predicted values.
[0010] The measured value acquisition unit acquires measured values including electric values
(e.g., current values and voltage values) and temperature values of a plurality of
energy storage devices. The measured value can be acquired from sensors (current sensor,
voltage sensor, temperature sensor) of the plurality of energy storage devices included
in the energy storage system. The frequency of acquisition of the measured value can
be appropriately determined in accordance with the operation state of the energy storage
system, and the like. For example, in an operation state where a load fluctuation
is relatively large, the frequency of acquiring the measured value can be increased
(e.g., five minutes every hour). Further, in an operation state where the load fluctuation
is relatively small, the frequency of acquiring the measured value can be reduced
(e.g., five minutes every six hours).
[0011] The predicted value acquisition unit acquires predicted values including electric
values (e.g., voltage values) and temperature values of a plurality of energy storage
devices. The predicted value is not a value actually measured by the sensor, but a
value assumed in advance in accordance with environmental states such as installation
conditions of the plurality of energy storage devices and ambient temperature, and
means a calculated value or an estimated value, and means a calculated value or an
estimated value.
[0012] The determination unit determines the presence or absence of an abnormality factor
relating to the energy storage system based on the acquired measured value and predicted
value. Based on the measured current values flowing through the plurality of energy
storage devices, it can be determined whether the load is heavy or light, or whether
the load fluctuation is large or small. The voltage difference between the required
energy storage devices can be obtained based on the measured value of the voltage
of each of the plurality of energy storage devices. Further, the temperature difference
between the required energy storage devices can be obtained based on the measured
values of the temperatures of the plurality of energy storage devices. The determination
unit can determine the presence or absence of an abnormality factor (e.g., the abnormality
of the energy storage device (degradation earlier than assumed) or the abnormality
of the environment of the energy storage device) by taking into consideration the
measured values of the voltage difference and the temperature difference, the difference
between the measured value and the predicted value, and the like.
[0013] The abnormality factor determination apparatus may include a provision unit that
provides operation support information of the energy storage system based on a result
of the determination in the determination unit.
[0014] The provision unit provides the operation support information of the energy storage
system based on a result of the determination in the determination unit. For example,
when it is determined that the energy storage device is abnormal, the provision unit
can provide information such as load reduction and replacement of the energy storage
device. Further, when it is determined that the environment is abnormal, the provision
unit can provide information such as adjustment of air conditioning (e.g., lowering
the temperature, etc.) and can provide operation support information for supporting
the optimum operation of the energy storage system in accordance with the abnormality
factor.
[0015] The abnormality factor determination apparatus is provided with: a first calculation
unit that calculates a measured voltage difference and a measured temperature difference
between required energy storage devices based on the measured values acquired by the
measured value acquisition unit; and a second calculation unit that calculates a difference
between a measured value and a predicted value with respect to each of a voltage and
a temperature of one of the required energy storage devices based on the measured
values acquired by the measured value acquisition unit and the predicted values acquired
by the predicted value acquisition unit. The determination unit may determine the
presence or absence of the abnormality factor based on the measured current value
acquired by the measured value acquisition unit, the measured voltage difference and
the measured temperature difference calculated by the first calculation unit, and
the difference between the measured value and the predicted value calculated by the
second calculation unit.
[0016] The first calculation unit calculates a measured voltage difference and a measured
temperature difference between required energy storage devices based on the measured
values acquired by the measured value acquisition unit.
[0017] The second calculation unit calculates the difference between the measured value
and the predicted value with respect to each of the voltage and temperature of one
of the required energy storage devices based on the measured value acquired by the
measured value acquisition unit and the predicted value acquired by the predicted
value acquisition unit.
[0018] The determination unit determines the presence or absence of an abnormality factor
based on the measured current value acquired by the measured value acquisition unit,
the measured voltage difference and the measured temperature difference calculated
by the first calculation unit, and the difference between the measured value and the
predicted value calculated by the second calculation unit. For example, when the measured
current value and the measured voltage difference between the energy storage devices
are large and the difference between the measured value and the predicted value is
also large, it can be determined that the one storage device is abnormal. On the other
hand, when the measured current value and the measured voltage difference between
the energy storage devices are large, but the difference between the measured value
and the predicted value is small, it can be determined that the state is within assumption
(not abnormal) due to, for example, the differences in the arrangement and installation
conditions between the energy storage devices in the energy storage system, deviations
in SOC between the energy storage devices, or the like.
[0019] When the measured current value is small, the measured temperature difference between
the energy storage devices is large, and the difference between the measured value
and the predicted value is also large, it can be determined that the environment is
abnormal. On the other hand, when the measured current value is small and the measured
temperature difference between the energy storage devices is large, but the difference
between the measured value and the predicted value is small, it can be determined
that the state is within assumption (not abnormal) due to the differences in the arrangement
and installation conditions between the energy storage devices in the energy storage
system, or the like.
[0020] In the abnormality factor determination apparatus, the determination unit may determine
whether the abnormality factor is the abnormality of the energy storage device or
the abnormality of an environment of the energy storage device.
[0021] The determination unit determines whether the abnormality is the abnormality of the
energy storage device or the abnormality of the environment of the energy storage
device as the abnormality factor. The abnormality of the energy storage device includes,
for example, a case where it is determined that the energy storage device deteriorates
earlier than assumed. Further, since the abnormality of the energy storage device
and the abnormality of the environment can be discriminated and determined, it is
possible to prevent erroneous determination of the abnormality of the energy storage
device.
[0022] The abnormality factor determination apparatus is provided with a learning apparatus
caused to learn based on learning data having, as input data, the measured current
values of the plurality of energy storage devices, the measured voltage difference
and the measured temperature difference between the required energy storage devices,
and the difference between the measured value and the predicted value with respect
to each of the voltage and the temperature of one of the required energy storage devices,
the learning data having the abnormality factor as output data. The determination
unit may input to the learning unit the measured current value acquired by the measured
value acquisition unit, the measured voltage difference and the measured temperature
difference calculated by the first calculation unit, and the difference between the
measured value and the predicted value calculated by the second calculation unit,
and determines the presence or absence of an abnormality factor.
[0023] The learning apparatus has learned based on learning data having, as input data,
the measured current values of the plurality of energy storage devices, the measured
voltage difference and the measured temperature difference between the required energy
storage devices, and the difference between the measured value and the predicted value
with respect to each of the voltage and the temperature of one of the required energy
storage devices, the learning data having the abnormality factor as output data.
[0024] The learning apparatus has learned so as to output the abnormality of the one storage
device when, for example, the measured current value and the measured voltage difference
between the energy storage devices are large and the difference between the measured
value and the predicted value is also large. The learning apparatus has learned so
as to output a state within assumption (not abnormal) when the measured current value
and the measured voltage difference between the energy storage devices are large and
the difference between the measured value and the predicted value is small.
[0025] The learning apparatus has learned so as to output that the environment is abnormal
when the measured current value is small, the measured temperature difference between
the energy storage devices is large, and the difference between the measured value
and the predicted value is also large. The learning apparatus has learned so as to
output that the state is within assumption (not abnormal) when the measured current
value is small, the measured temperature difference between the energy storage devices
is large, and the difference between the measured value and the predicted value is
small.
[0026] The determination unit input into the learning apparatus the measured current value
acquired by the measured value acquisition unit, the measured voltage difference and
the measured temperature difference calculated by the first calculation unit, and
the difference between the measured value and the predicted value calculated by the
second calculation unit, and determines the presence or absence of an abnormality
factor. It is thereby possible to determine an abnormality factor (e.g., the abnormality
of the energy storage device (degradation earlier than assumed, or the like) or the
abnormality of the environment of the energy storage device). Further, since the abnormality
of the energy storage device and the abnormality of the environment can be discriminated
and determined, it is possible to prevent erroneous determination of the abnormality
of the energy storage device.
[0027] A degradation determination apparatus for determining degradation of an energy storage
device is provided with: a measured data acquisition unit that acquires measured time-series
data including a measured electric value and a measured temperature value of the energy
storage device; a predicted data acquisition unit that acquires predicted time-series
data including a predicted electric value and a predicted temperature value of the
energy storage device; and a learning processing unit that causes a learning model
to learn based on learning data having the measured time-series data and the predicted
time-series data as input data and having determination of degradation of the energy
storage device as output data.
[0028] A computer program, which causes a computer to determine degradation of an energy
storage device, causes the computer to perform processing of acquiring measured time-series
data that includes a measured electric value and a measured temperature value of the
energy storage device, processing of acquiring predicted time-series data that includes
a predicted electric value and a predicted temperature value of the energy storage
device, and processing of causing a learning model to learn based on learning data
having the measured time-series data and the predicted time-series data as input data
and having determination of degradation of the energy storage device as output data.
[0029] A degradation determining method for determining degradation of an energy storage
device includes: acquiring measured time-series data that includes a measured electric
value and a measured temperature value of the energy storage device; acquiring predicted
time-series data that includes a predicted electric value and a predicted temperature
value of the energy storage device; and causing a learning model to learn based on
learning data having the measured time-series data and the predicted time-series data
as input data and determination of degradation of the energy storage device as output
data.
[0030] The measured data acquisition unit acquires measured time-series data including a
measured electric value and a measured temperature value of the energy storage device.
The electrical value includes voltage and current. The measured electric value includes,
for example, a voltage value measured by the voltage sensor and a current value measured
by a current sensor. The measured temperature value is a temperature measured by the
temperature sensor.
[0031] The predicted data acquisition unit acquires predicted time-series data including
a predicted electric value and a predicted temperature value of the energy storage
device. The predicted electric value or the predicted temperature value is not a value
actually measured by the sensor, but a value assumed in advance in accordance with
environmental states such as installation conditions of the energy storage device
and ambient temperature, and means a calculated value or an estimated value.
[0032] The learning processing unit causes a learning model to learn based on learning data
having the measured time-series data and the predicted time-series data as input data
and determination of degradation of the energy storage device as output data. The
learning model learns not only the measured time-series data including the measured
electric value and the measured temperature value of the energy storage device but
also predicted time-series data including the predicted electric value and the predicted
temperature value of the energy storage device. That is, it is possible to learn how
the measured electric value and the measured temperature value of the energy storage
device change and how the predicted electric value and the predicted temperature value
of the energy storage device change to determine whether the energy storage device
is normal or has been degraded. Since the predicted time-series data is data that
is assumed in accordance with environmental states such as installation conditions
of the energy storage device and ambient temperature, the learning model can learn
the charge-discharge behavior of the energy storage device due to the environmental
difference.
[0033] Hence, it is possible to generate a learning-completed learning model that can accurately
determine the degradation of the energy storage device even when there are environmental
differences such as installation conditions of the energy storage device and ambient
temperature.
[0034] A degradation determination apparatus for determining degradation of an energy storage
device is provided with: a measured data acquisition unit that acquires measured time-series
data including a measured electric value and a measured temperature value of the energy
storage device; a predicted data acquisition unit that acquires predicted time-series
data including a predicted electric value and a predicted temperature value of the
energy storage device; and a learning-completed learning model that uses the measured
time-series data and the predicted time-series data as input data to output determination
of degradation of the energy storage device.
[0035] A computer program, which causes a computer to determine degradation of an energy
storage device, causes the computer to perform processing of acquiring measured time-series
data that includes a measured electric value and a measured temperature value of the
energy storage device, processing of acquiring predicted time-series data that includes
a predicted electric value and a predicted temperature value of the energy storage
device, and processing of inputting the measured time-series data and the predicted
time-series data into a learning-completed learning model to determine degradation
of the energy storage device.
[0036] A degradation determining method for determining degradation of an energy storage
device includes: acquiring measured time-series data that includes a measured electric
value and a measured temperature value of the energy storage device; acquiring predicted
time-series data that includes a predicted electric value and a predicted temperature
value of the energy storage device; and inputting the measured time-series data and
the predicted time-series data into a learning-completed learning model to determine
degradation of the energy storage device.
[0037] The learning-completed learning model uses the measured time-series data and the
predicted time-series data as input data to output the determination of the deterioration
of the energy storage device. The learning-completed learning model has learned how
the measured electric value and the measured temperature value of the energy storage
device change and how the predicted electric value and the predicted temperature value
of the energy storage device change to determine whether the energy storage device
is normal or has been degraded. Since the predicted time-series data is data that
is assumed in accordance with environmental states such as installation conditions
of the energy storage device and ambient temperature, the learning-completed learning
model has learned the charge-discharge behavior of the energy storage device due to
the environmental difference.
[0038] Hence, it is possible to accurately determine the degradation of the energy storage
device even when there are environmental differences such as installation conditions
of the energy storage device and ambient temperature.
[0039] In the degradation determination apparatus, the learning processing unit may cause
the learning model to learn based on learning data having, as input data, respective
pieces of time-series data of a difference or a ratio between the measured electric
value and the predicted electric value and a difference or a ratio between the measured
temperature value and the predicted temperature value.
[0040] The learning processing unit causes the learning model to learn based on learning
data having, as input data, respective pieces of time-series data of a difference
or a ratio between the measured electric value and the predicted electric value and
a difference or a ratio between the measured temperature value and the predicted temperature
value.
[0041] The learning model can learn how the difference or the ratio between the measured
electric value and the predicted electric value changes to determine whether the energy
storage device is normal or has been degraded. The learning model can learn how the
difference or the ratio between the measured temperature value and the predicted temperature
value changes to determine whether the energy storage device is normal or has been
degraded. Thus, the learning model can learn the charge-discharge behavior of the
energy storage device due to the environmental difference.
[0042] In the degradation determination apparatus, the measured data acquisition unit may
acquire measured time-series data including a measured voltage value of the energy
storage device, the predicted data acquisition unit may acquire predicted time-series
data including a predicted voltage value of the energy storage device, and the learning
processing unit may causes the learning model to learn based on learning data having
the measured time-series data that includes the measured voltage value and the predicted
time-series data that includes the predicted voltage value as input data.
[0043] The measured data acquisition unit acquires measured time-series data including a
measured voltage value of the energy storage device. The predicted data acquisition
unit acquires predicted time-series data including a predicted voltage value of the
energy storage device. The learning processing unit causes a learning model to learn
based on learning data having the measured time-series data that includes the measured
voltage value and the predicted time-series data that includes the predicted voltage
value as input data.
[0044] The learning model can learn how the measured voltage value and the predicted voltage
value changes to determine whether the energy storage device is normal or has been
degraded. Thus, the learning model can learn whether the energy storage device is
normal or has been degraded in accordance with an assumed voltage difference.
[0045] In the degradation determination apparatus, the measured data acquisition unit may
acquire measured time-series data including a measured current value of the energy
storage device, the predicted data acquisition unit may acquire predicted time-series
data including a predicted current value of the energy storage device, and the learning
processing unit may cause the learning model to learn based on learning data having
the measured time-series data that includes the measured current value and the predicted
time-series data that includes the predicted current value as input data.
[0046] The measured data acquisition unit acquires measured time-series data including a
measured current value of the energy storage device. The predicted data acquisition
unit acquires predicted time-series data including a predicted current value of the
energy storage device. The learning processing unit causes the learning model to learn
based on learning data having the measured time-series data that includes the measured
current value and the predicted time-series data that includes the predicted current
value as input data.
[0047] The learning model can learn how the measured current value and the predicted current
value change to determine whether the energy storage device is normal or has been
degraded. Hence, the learning model can learn whether the energy storage device is
normal or has been degraded in accordance with the assumed current difference.
[0048] In the degradation determination apparatus, the measured data acquisition unit acquires
measured time-series data including a difference or a ratio between a measured electric
value of each of the plurality of energy storage cells forming the energy storage
module and an average value of the measured electric values of the plurality of energy
storage cells, and the learning processing unit causes the learning model to learn
based on learning data having measured time-series data that includes the difference
or the ratio as input data.
[0049] The measured data acquisition unit acquires measured time-series data including a
difference or a ratio between a measured electric value of each of the plurality of
energy storage cells forming the energy storage module and an average value of the
measured electric values of the plurality of energy storage cells. That is, the measured
time-series data including the difference or the ratio between the average value acquired
by averaging the actual measured electric values of the plurality of energy storage
cells and the actual measured electric values of the plurality of energy storage cells
are acquired.
[0050] The learning processing unit causes the learning model to learn based on learning
data having measured time-series data that includes the difference or the ratio as
input data. Thus, the learning model can learn how the difference or the ratio between
the average value obtained by averaging the measured electric values of the plurality
of energy storage cells and the measured electric values of the plurality of energy
storage cells changes to determine whether the energy storage device is normal or
has been degraded. The learning model can learn whether the energy storage device
is normal or has been degraded in accordance with the measured electric value between
the energy storage cells.
[0051] In the degradation determination apparatus, the predicted data acquisition unit acquires
predicted time-series data including a difference or a ratio between a predicted electric
value of each of the plurality of energy storage cells forming the energy storage
module and an average value of the predicted electric values of the plurality of energy
storage cells, and the learning processing unit causes the learning model to learn
based on learning data having predicted time-series data that includes the difference
or the ratio as input data.
[0052] The predicted data acquisition unit acquires predicted time-series data including
a difference or a ratio between a predicted electric value of each of the plurality
of energy storage cells forming the energy storage module and an average value of
the predicted electric values of the plurality of energy storage cells. That is, the
predicted data acquisition unit acquires the measured time-series data including the
difference or the ratio between the average value acquired by averaging the predicted
electric values of the plurality of energy storage cells and the predicted electric
value of each of the plurality of energy storage cells.
[0053] The learning processing unit causes the learning model to learn based on learning
data having the predicted time-series data that includes the difference or the ratio
as input data. Hence the learning model can learn how the difference or the ratio
between the average value obtained by averaging the predicted electric values of the
plurality of energy storage cells and the predicted electric values of the plurality
of energy storage cells changes to determine whether the energy storage device is
normal or has been degraded. Thus, the learning model can learn whether the energy
storage device is normal or has been degraded in accordance with the prior environmental
difference between the energy storage cells.
[0054] In the degradation determination apparatus, the predicted data acquisition unit acquires
predicted time-series data including a difference or a ratio between a predicted temperature
value of each of the plurality of energy storage cells forming the energy storage
module and an average value of the predicted temperature values of the plurality of
energy storage cells, and the learning processing unit causes the learning model to
learn based on learning data having predicted time-series data that includes the difference
or the ratio as input data.
[0055] The predicted data acquisition unit acquires predicted time-series data including
a difference or a ratio between a predicted temperature value of each of the plurality
of energy storage cells forming the energy storage module and an average value of
the predicted temperature values of the plurality of energy storage cells. That is,
the predicted time-series data including the difference or the ratio between the average
value acquired by averaging the predicted temperature values of the plurality of energy
storage cells and the predicted temperature values of the plurality of energy storage
cells. The predicted temperature value of each of the plurality of energy storage
cells can be obtained based on the predicted current value flowing in the energy storage
cell, the arrangement status of the energy storage cells in the energy storage module,
the predicted temperature value of the energy storage module, and the like.
[0056] The learning processing unit causes the learning model to learn based on learning
data having the predicted time-series data that includes the difference or the ratio
as input data. Hence the learning model can learn how the difference or the ratio
between the average value obtained by averaging the predicted temperature values of
the plurality of energy storage cells and the predicted temperature values of the
plurality of energy storage cells changes to determine whether the energy storage
device is normal or has been degraded. Thus, the learning model can learn whether
the energy storage device is normal or has been degraded in accordance with the prior
environmental difference between the energy storage cells.
[0057] In the degradation determination apparatus, the measured data acquisition unit acquires
measured time-series data including a measured pressure value of the energy storage
device, the predicted data acquisition unit acquires predicted time-series data including
a predicted pressure value of the energy storage device, and the learning processing
unit causes the learning model to learn based on learning data having time-series
data that includes a difference or a ratio between the measured pressure value and
the predicted pressure value as input data.
[0058] The measured data acquisition unit acquires measured time-series data including a
measured pressure value of the energy storage device. The predicted data acquisition
unit acquires the predicted time-series data including the predicted pressure value
of the energy storage device. The learning processing unit causes the learning model
to learn based on learning data having time-series data that includes a difference
or a ratio between the measured pressure value and the predicted pressure value as
input data.
[0059] The learning model can learn how the measured pressure value and the predicted pressure
value change to determine whether the energy storage device is normal or has been
degraded. Thus, the learning model can learn whether the energy storage device is
normal or has been degraded in accordance with the assumed pressure difference.
[0060] In the degradation determination apparatus, the learning processing unit causes the
learning model to learn based on learning data having presence or absence of an environmental
abnormality relating to the energy storage device as output data.
[0061] The learning processing unit causes the learning model to learn based on learning
data having presence or absence of an environmental abnormality relating to the energy
storage device as output data. By causing the learning model to learn the presence
or absence of an environmental abnormality, for example, it is possible to learn not
only the degradation of the energy storage device but also that there is an environmental
abnormality, and also to distinguish and determine the degradation of the energy storage
device from the environmental abnormality.
[0062] The degradation determination apparatus may determine the degradation of the energy
storage device by using a learning-completed learning model caused to learn by the
learning processing unit.
[0063] The learning processing unit determines the degradation of the energy storage device
by using the learning-completed learning model caused to learn by the learning processing
unit. Hence, it is possible to accurately determine the degradation of the energy
storage device even when there are environmental differences such as installation
conditions of the energy storage device and ambient temperature.
ADVANTAGES OF THE INVENTION
[0064] With the configuration described above, it is possible to determine an abnormality
factor relating to the energy storage system and to provide operation support information
that supports the optimum operation of the energy storage system in accordance with
the abnormality factor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0065]
Fig. 1 is a diagram showing an outline of a remote monitoring system of the present
embodiment.
Fig. 2 is a block diagram showing an example of the configuration of the remote monitoring
system.
Fig. 3 is a diagram showing an example of a connection mode of a communication device.
Fig. 4 is a block diagram showing an example of a configuration of a server apparatus.
Fig. 5 is a schematic diagram showing an example of a configuration of a learning
model.
Fig. 6 is a schematic diagram showing an example of a temperature distribution of
an energy storage cell in the energy storage module.
Fig. 7 is a schematic diagram showing an example of a difference in behavior of an
energy storage device due to an environmental difference.
Fig. 8 is a schematic diagram showing another example of the difference in the behavior
of the energy storage device due to the environmental difference.
Fig. 9 is a schematic diagram showing an example of time-series data of the voltage
of the energy storage device.
Fig. 10 is a schematic diagram showing an example of time-series data of the temperature
of the energy storage device.
Fig. 11 is a schematic diagram showing an example of time-series data of the voltage
and the average voltage of each energy storage cell.
Fig. 12 is a schematic diagram showing an example of time-series data of the temperature
and the average temperature of each energy storage cell.
Fig. 13 is a configuration diagram showing a first example of learning data.
Fig. 14 is a configuration diagram showing a second example of learning data.
Fig. 15 is a configuration diagram showing a third example of learning data.
Fig. 16 is a schematic diagram showing an example of processing of a learning model
in a learning mode.
Fig. 17 is a schematic diagram showing an example of processing of the learning model
in the determination mode.
Fig. 18 is a flowchart showing an example of a processing procedure of a processing
unit in the learning mode.
Fig. 19 is a flowchart showing an example of the processing procedure of the processing
unit in the determination mode.
Fig. 20 is a block diagram showing an example of the configuration of the server apparatus
serving as the abnormality factor determination apparatus according to the second
embodiment.
Fig. 21 is an explanatory diagram showing an example of a relationship between a measured
value and a predicted value.
Fig. 22 is a schematic diagram showing a first example of changes in a measured value
and a predicted value in a use state of an energy storage system.
Fig. 23 is a schematic diagram showing a second example of the changes in the measured
value and the predicted value in the use state of the energy storage system.
Fig. 24 is an explanatory diagram showing an example of a rule-based model for determining
an abnormality factor.
Fig. 25 is a schematic diagram showing an example of the configuration of the learning
model.
Fig. 26 is a flowchart showing an example of the processing procedure of the server
apparatus according to the second embodiment.
MODE FOR CARRYING OUT THE INVENTION
(First embodiment)
[0066] A degradation determination apparatus according to the present embodiment will be
described below with reference to the drawings. Fig. 1 is a diagram showing an outline
of a remote monitoring system 100 of the present embodiment. As shown in Fig. 1, a
thermal power generation system F, a mega solar power generation system S, a wind
power generation system W, a uninterruptible power supply (UPS) U, a rectifier (d.c.
power supply or a.c. power supply) D disposed in a stabilized power supply system
for railways, and the like are connected to a network N including a public communication
network (e.g., the Internet) N1, a carrier network N2 that achieves wireless communication
based on a mobile communication standard, and the like. A communication device 1 to
be described later, a server apparatus 2 that collects information from the communication
device 1 and serves as a degradation determination apparatus, and a client apparatus
3 that acquires the collected information are connected to the network N.
[0067] More specifically, the carrier network N2 includes a base station BS, and the client
apparatus 3 can communicate with the server apparatus 2 from the base station BS via
the network N. An access point AP is connected to the public communication network
N1, and the client apparatus 3 can transmit and receive information to and from the
server apparatus 2 via the network N from the access point AP.
[0068] A power conditioner (power conditioning system: PCS) P and an energy storage system
101 are attached to a mega solar power generation system S, a thermal power generation
system F and a wind power generation system W. The energy storage system 101 is configured
by juxtaposing a plurality of containers C each housing an energy storage module group
L. The energy storage module group L has a hierarchical structure of, for example,
an energy storage module (also called a module) in which a plurality of energy storage
cells (also called a cell) are connected in series, a bank in which a plurality of
energy storage modules are connected in series, and a domain in which a plurality
of banks are connected in parallel. The energy storage device is preferably rechargeable,
such as a secondary battery like a lead-acid battery or a lithium ion battery, or
a capacitor. Apart of the energy storage device may be a primary battery that is not
rechargeable.
[0069] Fig. 2 is a block diagram showing an example of the configuration of the remote monitoring
system 100. The remote monitoring system 100 includes the communication device 1,
a server apparatus 2, a client apparatus 3, and the like.
[0070] As shown in Fig. 2, the communication device 1 is connected to the network N and
is also connected to the target apparatuses P, U, D, M. The target apparatuses P,
U, D, M include a power conditioner P, an uninterruptible power supply U, a rectifier
D, and a management apparatus M to be described later.
[0071] In the remote monitoring system 100, the state (e.g., voltage, current, temperature,
state of charge (SOC)) of the energy storage module (energy storage cell) in the energy
storage system 101 is monitored and collected by using the communication device 1
connected to each of the target apparatuses P, U, D, M. The remote monitoring system
100 presents the detected state (including a state of degradation) of the energy storage
cell so that a user or an operator (a person in charge of maintenance) can confirm
the detected state.
[0072] The communication device 1 includes a control unit 10, a storage unit 11, a first
communication unit 12, and a second communication unit 13. The control unit 10 is
made of a central processing unit (CPU) or the like, and controls the entire communication
device 1 by using built-in memories such as read-only memory (ROM) and random-access
memory (RAM).
[0073] The storage unit 11 may be a nonvolatile memory such as a flash memory. The storage
unit 11 stores a device program 1P to be read and executed by the control unit 10.
The storage unit 11 stores information such as information collected by the processing
of the control unit 10 and event logs.
[0074] The first communication unit 12 is a communication interface for achieving communication
with the target apparatuses P, U, D, M and can use, for example, a serial communication
interface such as RS-232 C or RS-485.
[0075] The second communication unit 13 is an interface for achieving communication via
the network N and uses, for example, a communication interface such as an Ethernet
(registered trademark) or a wireless communication antenna. The control unit 10 can
communicate with the server apparatus 2 via the second communication unit 13.
[0076] The client apparatus 3 may be a computer used by the operator such as a manager of
the energy storage system 101 of the power generation systems S, F or a person in
charge of maintenance of the target apparatuses P, U, D, M. The client apparatus 3
may be a desktop type or a laptop type personal computer or may be a smartphone or
a tablet type communication terminal. The client apparatus 3 includes a control unit
30, a storage unit 31, a communication unit 32, a display unit 33, and an operation
unit 34.
[0077] The control unit 30 is a processor using a CPU. A control unit 30 causes a display
unit 33 to display a Web page provided by the server apparatus 2 or the communication
device 1 based on a Web browser program stored in a storage unit 31.
[0078] The storage unit 31 uses a nonvolatile memory such as a hard disk or a flash memory.
The storage unit 31 stores various programs including a Web browser program.
[0079] The communication unit 32 can use a communication device such as a network card for
wired communication, a wireless communication device for mobile communication connected
to a base station BS (see Figure 1), or a wireless communication device corresponding
to connection to the access point AP. The control unit 30 enables communication connection
or transmission and reception of information between the server apparatus 2 or the
communication device 1 via the network N by the communication unit 32
[0080] The display unit 33 may be a liquid crystal display, an organic electroluminescence
(EL) display, or the like. The display unit 33 can display an image of a Web page
provided by the server apparatus 2 by processing based on the Web browser program
of the control unit 30.
[0081] The operation unit 34 is a user interface, such as a keyboard and a pointing device,
capable of input and output with the control unit 30 or a voice input unit. A touch
panel of the display unit 33 or a physical button provided in the housing may be used
for the operation unit 34. The operation unit 34 notifies information of operation
by the user to the control unit 20.
[0082] The configuration of the server apparatus 2 will be described later.
[0083] Fig. 3 is a diagram showing an example of the connection mode of the communication
device 1. As shown in Fig. 3, the communication device 1 is connected to the management
apparatus M. Management apparatuses M provided in banks # 1 to # N, respectively,
are connected to the management apparatus M. Note that the communication device 1
may be a terminal apparatus (measurement monitor) that communicates with the management
apparatuses M provided in each of the banks # 1 to # N to receive information on the
energy storage devices, or may be a network card type communication device that can
be connected to a power-supply-related apparatus.
[0084] Each of the banks # 1 to # N includes a plurality of energy storage modules 60, and
each energy storage module 60 comprises a control board (cell monitoring unit: CMU)
70. The management apparatus M provided for each bank can communicate with the control
board 70 with a communication function built in each energy storage module 60 by serial
communication and can transmit and receive information to and from the management
apparatus M connected to a communication device 1. The management apparatus M connected
to the communication device 1 aggregates information from each management apparatus
M of the bank belonging to a domain and outputs the aggregated information to the
communication device 1.
[0085] Fig. 4 is a block diagram showing an example of the configuration of the server apparatus
2. The server apparatus 2 includes a control unit 20, a communication unit 21, a storage
unit 22, and a processing unit 23. The processing unit 23 includes a predicted data
generation unit 24, a learning data generation unit 25, a learning model 26, a learning
processing unit 27, and an input data generation unit 28. The server apparatus 2 may
be a single server computer, but is not limited to this, and may be made up of a plurality
of server computers.
[0086] The control unit 20 can be made of, for example, a CPU, and controls the entire server
apparatus 2 by using built-in memories such as ROM and RAM. The control unit 20 executes
information processing based on a server program 2P stored in the storage unit 22.
The server program 2P includes a Web server program, and the control unit 20 functions
as a Web server that performs provision of a Web page to the client apparatus 3, reception
of a login to a Web service, and the like. The control unit 20 can also collect information
from the communication device 1 as a simple network management protocol) (SNMP) server
based on the server program 2P.
[0087] The communication unit 21 is a communication device that achieves the communication
connection and the transmission and reception of data via the network N. Specifically,
the communication unit 21 is a network card corresponding to the network N.
[0088] The storage unit 22 may be a nonvolatile memory such as a hard disk or a flash memory.
The storage unit 22 stores sensor information (e.g., measured voltage data, measured
current data, measured temperature data, and measured pressure data of the energy
storage device) that includes the states of the target apparatuses P, U, D, M to be
monitored and is collected by the processing of the control unit 20.
[0089] The processing unit 23 can acquire sensor information (measured voltage data in
time series, measured current data in time series, measured temperature data in time
series, and measured pressure data in time series) of the energy storage devices (energy
storage modules, energy storage cells) collected in the database of the storage unit
22, by classifying the information into each energy storage device.
[0090] The processing unit 23 operates in a learning mode for learning the learning model
26 and in a determination mode for determining the presence or absence of degradation
of the energy storage device and an abnormality of the environment (environmental
abnormality) in which the energy storage device is installed by using the learning-completed
learning model 26.
[0091] Fig. 5 is a schematic diagram showing an example of the configuration of the learning
model 26. The learning model 26 is a neural network model including deep learning
and is made up of an input layer, an output layer, and a plurality of intermediate
layers. Although two intermediate layers are shown in Fig. 5 for convenience, the
number of intermediate layers is not limited to two but may be three or more.
[0092] In the input layer, the output layer, and the intermediate layer, there are one or
more nodes (neurons), and the node of each layer is coupled in one direction with
a desired weight to each of the nodes existing in the preceding and succeeding layers.
A vector having the same number of components as the number of nodes of an input layer
is provided as input data of the learning model 26 (input data for learning and input
data for determination). The input data includes energy storage device information
(SOC, full charge capacity, SOC-OCV (open circuit voltage) curve, internal resistance,
etc.), measured value time-series data (voltage, current, temperature, pressure, etc.),
predicted value time-series data (voltage, current, temperature, pressure, etc.),
and the like. The output data includes determination of degradation of the energy
storage device and the presence or absence of an environmental abnormality. Details
of these information will be described later.
[0093] The data provided to each node of the input layer is input into the first intermediate
layer, where the output of the intermediate layer is calculated using weights and
activation functions, and the calculated values are provided to the next intermediate
layer and are similarly transferred to subsequent layers (lower layer) in sequence
until the output of the output layer is obtained in the same manner. Note that all
the weights combining the nodes are calculated by a learning algorithm.
[0094] The output data can be data in a vector format having components of the same size
as the number of nodes (size of the output layer) of the output layer. For example,
as shown in Fig. 5, the number of nodes of the output layer can be 4, and the output
nodes can be a probability that the energy storage device is in a degraded state,
a probability that the energy storage device is normal, a probability that the environment
is abnormal, a probability that the environment is normal, and the like.
[0095] The learning model 26 and the learning processing unit 27 can be configured, for
example, by combining hardware such as a CPU (e.g., multiple processors mounted with
a plurality of processor cores, etc.), a graphics processing unit (GPU), a digital
signal processor (DSP), a field-programmable gate array (FPGA), and the like. A quantum
processor can also be combined. The learning model 26 is not limited to a neural network
model but may be other machine learning models.
[0096] Fig. 6 is a schematic diagram showing an example of a temperature distribution of
an energy storage cell in the energy storage module. In Fig. 6, for convenience, the
temperature distribution is classified into three groups of high (fairly high), medium
(somewhat high), and low (usual), but the actual temperature distribution can be expressed
in more detail (e.g., in 1-°C increments). The temperature distribution can be assumed
(predicted) in advance based on various environmental factors such as the placement
of each energy storage cell in the energy storage module, the value of current flowing
through the energy storage module (energy storage cell), the installation conditions
of the energy storage module, and the ambient temperature of the energy storage module.
In the example of Fig. 6, it can be seen that the temperature of the energy storage
cell disposed near the center is higher than that of the energy storage module disposed
outside and that the temperature of the upper side of the energy storage module is
higher than that of the lower side. As described above, it can be said that the temperature
difference between the energy storage cells appears as a result of aggregation of
various environmental factors.
[0097] Fig. 7 is a schematic diagram showing an example of a difference in the behavior
of the energy storage device due to an environmental difference. In Fig. 7, the vertical
axis represents the voltage, and the horizontal axis represents the time. The voltage
is, for example, a change when the energy storage device is being charged, but the
same applies in the case of discharge. In the example of Fig. 7, the environmental
difference is a temperature difference. In the figure, a curve indicated by symbol
B shows a change in the voltage of a normal energy storage device. If the change in
the voltage of the energy storage device of the curve indicated by symbol A is observed
without considering the temperature difference, since the voltage is high as compared
to the change in the voltage of the normal energy storage device indicated by symbol
B, it can be determined that, for example, the internal resistance of the energy storage
device has increased and the capacity has decreased, and three is a possibility that
the energy storage device of the curve indicated by symbol A is determined to be degraded.
In practice, however, the change in the voltage of the energy storage device of the
curve indicated by symbol A represents a change at a temperature considerably lower
than the temperature (high: ordinary) of the normal energy storage device indicated
by symbol B, and it can be said that the energy storage device of the curve indicated
by symbol A is within the normal range in consideration of the environmental difference
(temperature difference). On the other hand, a curve indicated by symbol C represents
a change in the voltage of the energy storage device, the change being more degraded
than assumed. Thus, when the environmental difference is not taken into consideration,
the normal energy storage device may be determined to have been degraded. In other
words, the consideration of the environmental difference makes it possible to prevent
an erroneous determination that a normal energy storage device has been degraded.
[0098] Fig. 8 is a schematic diagram showing another example of the difference in the behavior
of the energy storage device due to the environmental difference. In Fig. 8, the vertical
axis represents the full charge capacity (FCC), and the horizontal axis represents
the time. In the example of Fig. 8, the environmental difference is a temperature
difference. The full charge capacity is a capacity when the energy storage device
is fully charged. In the figure, a curve indicated by symbol A shows a change in a
full charge capacity of a normal energy storage device. If the change in the full
charge capacity of the energy storage device of the curve indicated by symbol B is
observed without considering the temperature difference, since the full charge capacity
is low as compared to the change in the full charge capacity of the normal energy
storage device indicated by symbol A, it can be determined that the degradation of
the energy storage device is progressing, and there is a possibility that the energy
storage device of the curve indicated by the symbol B is determined to have been deteriorated.
However, in practice, the change in the full charge capacity of the energy storage
device of the curve indicated by symbol B represents a change at a temperature considerably
higher than the temperature (low: ordinary) of the normal energy storage device indicated
by symbol A, and it can be said that the energy storage device of the curve indicated
by symbol B is within the normal range in consideration of the environmental difference
(temperature difference). On the other hand, the curve indicated by symbol C represents
a change in the full charge capacity of the energy storage device, the change being
more degraded than assumed. Thus, when the environmental difference is not taken into
consideration, the normal energy storage device may be determined to have been degraded.
In other words, the consideration of the environmental difference makes it possible
to prevent an erroneous determination that a normal energy storage device has been
degraded.
[0099] Fig. 9 is a schematic diagram showing an example of time-series data of the voltage
of the energy storage device. In Fig. 9, the vertical axis represents the voltage,
and the horizontal axis represents the time. The voltage is, for example, a change
when the energy storage device is being charged and discharged. In the figure, the
measured voltage data indicates a voltage value actually measured by the voltage sensor.
The predicted voltage data indicates a voltage value assumed in advance in consideration
of an assumed environmental difference of the energy storage device. When the difference
or the ratio between the measured voltage value and the predicted voltage value is
within a predetermined voltage threshold, it can be determined that the energy storage
device is in a state within assumption in consideration of the environmental difference
and is normal. However, when the difference or the ratio between the measured voltage
value and the predicted voltage value becomes larger than a predetermined voltage
threshold, it can be determined that the energy storage device has deviated from the
state within assumption and has been deteriorated (a position indicated by an arrow
in the figure). Note that this example is the case of the energy storage device degraded
more than assumed, and the difference or the ratio is within the error range in the
normal case. Even in the normal state, a deviation within a predetermined range occurs
due to a temperature difference.
[0100] That is, the learning model 26 can be caused to learn by the time-series data of
the difference or the ratio between the measured voltage value and the predicted voltage
value and the data relating to the determination of the degradation of the energy
storage device.
[0101] Fig. 10 is a schematic diagram showing an example of time-series data of the temperature
of the energy storage device. In Fig. 10, the vertical axis represents the temperature,
and the horizontal axis represents the time. The temperature is, for example, a change
when the energy storage device is being charged and discharged. In the figure, the
measured temperature data indicates the temperature value actually measured by the
temperature sensor. The predicted temperature data indicates a temperature value assumed
in advance in consideration of an assumed environmental difference of the energy storage
device. When the difference or the ratio between the measured temperature value and
the predicted temperature value is within a predetermined temperature threshold, it
can be determined that the energy storage device is in a state within assumption in
consideration of the environmental difference and that the device is normal. When
the difference or the ratio between the measured temperature value and the predicted
temperature value becomes larger than a predetermined temperature threshold, it can
be determined that the energy storage device has deviated from the assumed state and
has been deteriorated (a position indicated by an arrow in the figure).
[0102] That is, the learning model 26 can be caused to learn by the time-series data of
the difference or the ratio between the measured temperature value and the predicted
temperature value and the data relating to the determination of the degradation of
the energy storage device.
[0103] Although the voltage value and the temperature value have been described in the above
example, the present invention is not limited thereto. For example, the learning model
26 can be caused to learn by the time-series data of the difference or the ratio between
the measured current value and the predicted current value and the data relating to
the determination of the degradation of the energy storage device. Further, for example,
as shown in Fig. 6, in the energy storage module in which a plurality of energy storage
cells are stacked, the learning model 26 can be caused to learn by the time-series
data of the difference or the ratio between the measured pressure value and the predicted
pressure value of the pressure value between the cells and the data relating to the
determination of the degradation of the energy storage device.
[0104] Fig. 11 is a schematic diagram showing an example of the time-series data of the
voltage and the average voltage of each energy storage cell. In Fig. 11, the vertical
axis represents the voltage, and the horizontal axis represents the time. The voltage
is, for example, a change when the energy storage device is being charged and discharged.
For convenience, the energy storage cells are C1, C2, and C3. The figure shows the
voltage values of the energy storage cells C1, C2, C3 and the average values of the
voltage values of the energy storage cells C1, C2, C3. In consideration of the environmental
difference between the energy storage cells, each of the voltage values of the energy
storage cells C1, C2, C3 has a constant variation (acceptable variation when normal).
That is, when the difference or the ratio between each of the voltage values of the
energy storage cells C1, C2, C3 and the average value of the voltage values is within
a predetermined voltage threshold, it can be determined that the energy storage cell
is in a state within assumption in consideration of the environmental difference and
that the cell is normal. However, when the difference or the ratio between each of
the voltage values of the energy storage cells C1, C2, C3 and the average value becomes
larger than a predetermined voltage threshold, it can be determined that the energy
storage cell has deviated from the state within assumption and has been deteriorated
(a position indicated by an arrow in the figure).
[0105] That is, the learning model 26 can be caused to learn by the time-series data of
the difference or the ratio between each of the voltage values and the average value
of the plurality of energy storage cells and the data relating to the determination
of the degradation of the energy storage device. Note that the time-series data may
be time-series data of the measured value or time-series data of the predicted value.
The time-series data is not limited to a voltage value but may be a current value
or a pressure value.
[0106] Fig. 12 is a schematic diagram showing an example of time-series data of the temperature
and the average temperature of each energy storage cell. In Fig. 12, the vertical
axis represents the temperature, and the horizontal axis represents the time. The
temperature is, for example, a change when the energy storage device is being charged
and discharged. For convenience, the energy storage cells are C1, C2, and C3. The
figure shows the temperatures of the energy storage cells C1, C2, C3 and the average
values of the temperatures of the energy storage cells C1, C2, C3. In consideration
of the environmental difference between the energy storage cells, each of the temperatures
of the energy storage cells C1, C2, C3 has a constant variation (acceptable variation
when normal). That is, when the difference or the ratio between each of the temperatures
of the energy storage cells C1, C2, C3 and the average value of the temperatures is
within a predetermined voltage threshold, it can be determined that the energy storage
cell is in a state within assumption in consideration of the environmental difference
and that the cell is normal. However, when the difference or the ratio between each
of the temperatures of the energy storage cells C1, C2, C3 and the average value becomes
larger than a predetermined temperature threshold, it can be determined that the energy
storage cell has deviated from the state within assumption and has been deteriorated
(a position indicated by an arrow in the figure).
[0107] That is, the learning model 26 can be caused to learn by the time-series data of
the difference or the ratio between each of the temperature and the average value
of the plurality of energy storage cells and the data relating to the determination
of the degradation of the energy storage device. Note that the time-series data may
be time-series data of the measured value or time-series data of the predicted value.
[0108] In the following, first, the learning mode of the learning model 26 will be described.
[0109] The processing unit 23 acquires measured time-series data including a measured electric
value and a measured temperature value of the energy storage device. The electrical
value includes voltage and current. The measured electric value includes, for example,
a voltage value measured by the voltage sensor and a current value measured by a current
sensor. The measured temperature value is a temperature measured by the temperature
sensor.
[0110] The predicted data generation unit 24 generates predicted time-series data including
a predicted electric value and a predicted temperature value of the energy storage
device. The predicted electric value or the predicted temperature value is not a value
actually measured by the sensor, but a value assumed in advance in accordance with
environmental states such as installation conditions of the energy storage device
and ambient temperature, and means a calculated value or an estimated value.
[0111] The processing unit 23 can acquire predicted time-series data generated by the predicted
data generation unit 24, including the predicted electric value and the predicted
temperature value of the energy storage device.
[0112] The learning data generation unit 25 generates learning data having measured time-series
data and predicted time-series data as input data and having determination of degradation
of the energy storage device as output data.
[0113] The learning processing unit 27 causes the learning model 26 to learn based on the
generated learning data.
[0114] The learning data generation unit 25 need not be provided in the server apparatus
2 but the learning data generation unit 25 may be provided in another server apparatus,
the learning data generated in the server apparatus may be acquired, and the learning
processing unit 27 may cause the learning model 26 to learn based on the acquired
learning data. The same applies to the following description of the present specification.
[0115] The learning model 26 can learn not only the measured time-series data including
the measured electric value and the measured temperature value of the energy storage
device but also predicted time-series data including the predicted electric value
and the predicted temperature value of the energy storage device. That is, it is possible
to learn how the measured electric value and the measured temperature value of the
energy storage device change and how the predicted electric value and the predicted
temperature value of the energy storage device change to determine whether the energy
storage device is normal or has degraded. Since the predicted time-series data is
data that is assumed in accordance with environmental states such as installation
conditions of the energy storage device and ambient temperature, the learning model
26 can learn the charge-discharge behavior of the energy storage device due to the
environmental difference.
[0116] Hence, it is possible to generate the learning-completed learning model 26 that can
accurately determine the degradation of the energy storage device even when there
are environmental differences such as installation conditions of the energy storage
device and ambient temperature.
[0117] Fig. 13 is a configuration diagram showing a first example of the learning data.
The data shown in Fig. 13 shows input data for learning. As shown in Fig. 13, the
input data includes measured value data and predicted value data. The measured value
data and the predicted value data are time-series data (time t1, t2, t3,... tN) of
the voltage, current, temperature, and pressure of the energy storage device. For
example, the time-series data of the measured voltage value is represented by Va(t1),
Va(t2), Va(t3),..., and Va(tN), and the time-series data of the predicted voltage
value is represented by Ve(t1), Ve(t2), Ve(t3),..., and Ve(tN). The same applies to
other data.
[0118] The learning data generation unit 25 generates a learning data having, as input data,
the respective pieces of time-series data of the difference or the ratio between the
measured electric value and the predicted electric value and the difference or the
ratio between the measured temperature value and the predicted temperature value.
[0119] The learning model 26 can learn how the difference or the ratio between the measured
electric value and the predicted electric value changes to determine whether the energy
storage device is normal or has been degraded. The learning model 26 can learn how
the difference or the ratio between the measured temperature value and the predicted
temperature value changes to determine whether the energy storage device is normal
or has been degraded. Thus, the learning model 26 can learn the charge-discharge behavior
of the energy storage device due to the environmental difference.
[0120] Specifically, the learning data generation unit 25 can generate learning data having,
as input data, measured time-series data that includes a measured voltage value and
predicted time-series data that includes a predicted voltage value.
[0121] In this case, the learning model 26 can learn how the measured voltage value and
the predicted voltage value changes to determine whether the energy storage device
is normal or has been degraded. Thus, the learning model 26 can learn whether the
energy storage device is normal or has been degraded in accordance with the assumed
voltage difference.
[0122] The learning data generation unit 25 can generate learning data having the measured
time-series data including the measured current value and the predicted time-series
data that includes the predicted current value as input data.
[0123] In this case, the learning model 26 can learn how the measured current value and
the predicted current value change to determine whether the energy storage device
is normal or has been degraded. Hence, the learning model 26 can learn whether the
energy storage device is normal or has been degraded in accordance with the assumed
current difference.
[0124] The learning data generation unit 25 can generate learning data having time-series
data that includes the difference or the ratio between the measured pressure value
and the predicted pressure value as input data.
[0125] In this case, the learning model 26 can learn how the measured pressure value and
the predicted pressure value have changed to determine whether the energy storage
device is normal or has been degraded. Thus, the learning model 26 can learn whether
the energy storage device is normal or has been degraded in accordance with the assumed
pressure difference.
[0126] Fig. 14 is a configuration diagram showing a second example of the learning data.
The data shown in Fig. 14 shows input data for learning. As shown in Fig. 14, the
input data can be time-series data of the difference between the measured value and
the predicted value. Specifically, the data is time-series data (time t1, t2, t3,...
tN) of the voltage difference, the current difference, the temperature difference,
and the pressure difference. For example, the time-series data of the voltage difference
is represented by {Va(t1) - Ve(t1)}, {Va(t2) - Ve(t2)}, {Va(t3) - Ve(t3)},..., and
{Va(tN) - Ve(tN)}. The same applies to other data.
[0127] Fig. 15 is a configuration diagram showing a third example of learning data. The
data shown in Fig. 15 shows input data for learning. As shown in Fig. 15, the input
data can be time-series data of the ratio between the measured value and the predicted
value. Specifically, the data is time-series data (time t1, t2, t3,... tN) of the
voltage ratio, the current ratio, the temperature ratio, and the pressure ratio. For
example, the time-series data of the voltage ratio is represented by {Va(t1)/Ve(t1)},
{Va(t2)/Ve(t2)}, {Va(t3)/Ve(t3)},..., and {Va(tN)/Ve(tN)}. The same applies to other
data.
[0128] The learning data generation unit 25 can generate learning data having the presence
or absence of an environmental abnormality relating to the energy storage device as
output data. By causing the learning model 26 to learn the presence or absence of
an environmental abnormality, for example, it is possible to learn not only the degradation
of the energy storage device but also that there is an environmental abnormality,
and also to distinguish and determine the degradation of the energy storage device
from the environmental abnormality.
[0129] Fig. 16 is a schematic diagram showing an example of processing of the learning model
26 in the learning mode. As shown in Fig. 16, time-series data of time t1, t2, t3,...,
and tN are input into the learning model 26. The input time-series data is, for example,
data as illustrated in Figs. 13 to 15. An output value (e.g., either 1 or 0) can be
set in the output node of the learning model 26 in accordance with whether the input
data is data when the energy storage device is normal or has been degraded, the environment
is normal, or the environment is abnormal. For example, when the input data for learning
is data in the case where the energy storage device has been degraded, 1 may be set
in the output node of "Degradation of energy storage device," and 0 may be set in
the other output nodes. When the input data for learning is data in the case where
the environment is abnormal, 1 may be set in the output node of "Environmental abnormality"
and 0 may be set in the other output nodes. The output data in the learning mode may
be a probability when the energy storage device is normal or has been degraded, the
environment is normal, or the environment is abnormal. In this case, the learning
model 26 can be caused to learn so that the output value of the output node approaches
the probability.
[0130] Next, learning data in consideration of variations among energy storage cells will
be described.
[0131] The learning data generation unit 25 can generate learning data having, as input
data, measured time-series data that includes the difference or the ratio between
the measured electric value of each of the plurality of energy storage cells forming
the energy storage module and the average value of the measured electric values of
the plurality of energy storage cells. The electric value can be, for example, a voltage
value or a current value.
[0132] Hence the learning model 26 can learn how the difference or the ratio between the
average value obtained by averaging the measured electric values of the plurality
of energy storage cells and the measured electric values of the plurality of energy
storage cells changes to determine whether the energy storage device is normal or
has been degraded. Thus, the learning model 26 can learn whether the energy storage
device is normal or has been degraded in accordance with the measured electric value
between the energy storage cells.
[0133] The learning data generation unit 25 can generate learning data having, as input
data, predicted time-series data that includes the difference or the ratio between
each of the predicted electric values of the plurality of energy storage cells forming
the energy storage module and the average value of the predicted electric values of
the plurality of energy storage cells.
[0134] Hence the learning model 26 can learn how the difference or the ratio between the
average value obtained by averaging the predicted electric values of the plurality
of energy storage cells and the predicted electric values of the plurality of energy
storage cells changes to determine whether the energy storage device is normal or
has been degraded. Thus, the learning model 26 can learn whether the energy storage
device is normal or has been degraded in accordance with the prior environmental difference
between the energy storage cells.
[0135] The learning data generation unit 25 can generate learning data having, as input
data, predicted time-series data that includes the difference or the ratio between
each of the predicted temperature values of the plurality of energy storage cells
forming the energy storage module and the average value of the predicted temperature
values of the plurality of energy storage cells. The predicted temperature value of
each of the plurality of energy storage cells can be obtained based on the predicted
current value flowing in the energy storage cell, the arrangement status of the energy
storage cells in the energy storage module, the predicted temperature value of the
energy storage module, and the like.
[0136] Thus, the learning model 26 can learn how the difference or the ratio between the
average value obtained by averaging the predicted temperature values of the plurality
of energy storage cells and the predicted temperature values of the plurality of energy
storage cells changes to determine whether the energy storage device is normal or
has been degraded. Thus, the learning model 26 can learn whether the energy storage
device is normal or has been degraded in accordance with the prior environmental difference
between the energy storage cells.
[0137] Next, a determination mode by the learning-completed learning model 26 will be described.
[0138] The input data generation unit 28 generates input data including measured time-series
data and predicted time-series data.
[0139] Fig. 17 is a schematic diagram showing an example of processing of the learning model
26 in the determination mode. As shown in Fig. 17, time-series data of time t1, t2,
t3,..., and tN are input into the learning-completed learning model 26. The input
time-series data has the same structure as the data exemplified in Figs. 13 to 15,
for example. The learning-completed learning model 26 determines the degradation of
the energy storage device and the presence or absence of the environmental abnormality
based on the input time-series data. Note that it is not essential to determine the
presence or absence of the environmental abnormality, but only the degradation of
the energy storage device may be determined.
[0140] The probability of degradation of the energy storage device, the probability of normality
of the energy storage device, the probability of environmental abnormality, and the
probability of environmental normality are output in the output node of the learning-completed
learning model 26.
[0141] In this manner, the learning-completed learning model 26 can use the measured time-series
data and the predicted time-series data as input data to output the determination
of the deterioration of the energy storage device. The learning-completed learning
model 26 has learned how the measured electric value and the measured temperature
value of the energy storage device change and how the predicted electric value and
the predicted temperature value of the energy storage device change to determine whether
the energy storage device is normal or has been degraded. Since the predicted time-series
data is data that is assumed in accordance with environmental states such as installation
conditions of the energy storage device and ambient temperature, the learning-completed
learning model 26 has learned the charge-discharge behavior of the energy storage
device due to the environmental difference.
[0142] Hence, it is possible to accurately determine the degradation of the energy storage
device even when there are environmental differences such as installation conditions
of the energy storage device and ambient temperature.
[0143] Fig. 18 is a flowchart showing an example of the processing procedure of the processing
unit 23 in the learning mode. The processing unit 23 acquires measured time-series
data of the energy storage device (S11) and acquires predicted time-series data of
the energy storage device (S12).
[0144] The processing unit 23 generates learning data having the measured time-series data
and the predicted time-series data as input data and having the determination of the
degradation of the energy storage device as output data (S13). The processing unit
23 performs the learning and update of the learning model 26 based on the generated
learning data (S14) and determines whether or not to end the processing (S15). When
it is determined not to end the processing (NO in S15), the processing unit 23 continues
the processing from S11, and when it is determined to end the processing (YES in S15),
the processing is ended.
[0145] Fig. 19 is a flowchart showing an example of the processing procedure of the processing
unit 23 in the determination mode. The processing unit 23 acquires measured time-series
data of the energy storage device (S21) and acquires predicted time-series data of
the energy storage device (S22).
[0146] The processing unit 23 generates input data based on the measured time-series data
and the predicted time-series data (S23), determines the degradation of the energy
storage device (S24), and ends the processing.
[0147] As described above, according to the server apparatus 2 of the present embodiment,
since the detailed behavior of the energy storage device in the actual state of use
and the influence of the assigned environmental difference can also be learned by
the learning model 26 based on the sensor information detected by the energy storage
device operating in the mobile body or facility, it is not possible to accurately
determine the degradation of the energy storage device. Further, for example, it is
possible to determine the presence or absence of an environmental abnormality in which
the energy storage device appears abnormal even though being normal.
[0148] In the embodiment described above, the server apparatus 2 has been configured to
include the learning model 26 and the learning processing unit 27, but the present
invention is not limited thereto. For example, the learning model 26 and the learning
processing unit 27 may be provided in one or more other servers. The degradation determination
apparatus is not limited to the server apparatus 2. For example, an apparatus such
as a degradation determination simulator may be used.
(Second Embodiment)
[0149] The first embodiment described above has a configuration where whether the energy
storage device has been degraded earlier than assumed is determined by making a distinction
between a determination that the energy storage device has actually been degraded
and an erroneous determination that the energy storage has been degraded due to an
environmental difference even though being normal. However, it is also possible to
determine an abnormality factor of the energy storage system from the same viewpoint.
The second embodiment will be described below.
[0150] Fig. 20 is a block diagram showing an example of the configuration of the server
apparatus 2 serving as the abnormality factor determination apparatus according to
the second embodiment. The difference from the server apparatus 2 shown in Fig. 4
is that the processing unit 23 includes a first calculation unit 231, a second calculation
unit 232, an abnormality factor determination unit 233, and an operation support information
provision unit 234. The same parts are denoted by the same symbols and the description
thereof will be omitted.
[0151] The processing unit 23 has a function as the measured value acquisition unit and
acquires measured values of currents, voltages, and temperatures of a plurality of
energy storage devices. The measured value can be acquired from a value measured by
sensors (current sensor, voltage sensor, temperature sensor) of the plurality of energy
storage devices included in the energy storage system. The frequency of acquisition
of the measured value can be appropriately determined in accordance with the operation
state of the energy storage system, and the like. For example, in an operation state
where a load fluctuation is relatively large, the frequency of acquiring the measured
value can be increased (e.g., five minutes every hour). Further, in an operation state
where the load fluctuation is relatively small, the frequency of acquiring the measured
value can be reduced (e.g., five minutes every six hours).
[0152] The processing unit 23 has a function as the predicted value acquisition unit and
acquires predicted values of voltages and temperatures of a plurality of energy storage
devices. The predicted value is not a value actually measured by the sensor, but a
value assumed in advance in accordance with environmental states such as installation
conditions of the plurality of energy storage devices and ambient temperature, and
means a calculated value or an estimated value, and means a calculated value or an
estimated value. The predicted value may be generated in advance by the server apparatus
2 or by an external apparatus.
[0153] The first calculation unit 231 calculates a measured voltage difference and a measured
temperature difference between required energy storage devices based on the measured
values acquired by the processing unit 23.
[0154] The second calculation unit 232 calculates the difference between the measured value
and the predicted value with respect to each of the voltage and temperature of one
of the required energy storage devices based on the measured value and the predicted
value acquired by the processing unit 23.
[0155] Fig. 21 is an explanatory diagram showing an example of the relationship between
the measured value and the predicted value. Fig. 21 shows a state in which a plurality
of energy storage devices forming the energy storage system are connected in series.
As shown in Fig. 6, a plurality of energy storage cells are connected in series to
form one energy storage module. The energy storage module forms a plurality of banks
connected in series. The energy storage cells shown in Fig. 21, for example, illustrate
required two energy storage cells i, j among a plurality of energy storage cells forming
the bank. Note that the energy storage cells i, j can be selected from a plurality
of energy storage cells in accordance with the arrangement as shown in Fig. 6.
[0156] The current flowing through the energy storage cells i, j is expressed as a measured
cell current Ie. The measured cell voltage of the energy storage cell i is represented
by Vei, the measured cell voltage of the energy storage cell j is represented by Vej,
and the measured inter-cell voltage difference between the energy storage cells i,
j is represented by ΔV (ΔV = Vei-Vej).
[0157] The predicted cell voltage of the energy storage cell i is represented by Vci, and
the voltage difference between measured and predicted values of the energy storage
cell i is represented by ΔVeci (ΔVeci = Vei-Vci). The predicted cell voltage of the
energy storage cell j is expressed by Vbj, and the voltage difference between measured
and predicted values of the energy storage cell j is expressed by ΔVecj (ΔVecj = Vej-Vej).
[0158] The measured cell temperature of the energy storage cell i is represented by Tei,
the measured cell temperature of the energy storage cell j is represented by Tej,
and the measured inter-cell temperature difference between the energy storage cells
i, j is represented by ΔT(ΔT = Tei - Tej).
[0159] The predicted cell temperature of the energy storage cell i is represented by Vci,
and the difference between measured and predicted temperatures of the energy storage
cell i is represented by ΔTeci(ΔTeci = Tei - Tci). The predicted cell temperature
of the energy storage cell j is represented by Vcj, and the difference between measured
and predicted temperatures of the energy storage cell j is represented by ΔTecj (ΔTecj
= Tej - Tcj).
[0160] The abnormality factor determination unit 233 has a function as the determination
unit and determines the presence or absence of an abnormality factor relating to the
energy storage system based on the measured value and the predicted value acquired
by the processing unit 23. Based on the measured values of current (also referred
to as measured current values) flowing through the plurality of energy storage devices,
it can be determined whether the load is heavy or light, or whether the load fluctuation
is large or small. Further, as described above, the voltage difference between the
required energy storage devices can be obtained based on the measured value of the
voltage of each of the plurality of energy storage devices. Further, the temperature
difference between the required energy storage devices can be obtained based on the
measured values of the temperatures of the plurality of energy storage devices. The
abnormality factor determination unit 233 can discriminate and determine the presence
or absence of an abnormality factor, the type of the abnormality factor, for example,
the abnormality of the energy storage device (degradation earlier than assumed), the
abnormality of the environment of the energy storage device, or the state within assumption
(not abnormal) by taking into consideration the measured values of the voltage difference
and the temperature difference, the difference between the measured value and the
predicted value, and the like.
[0161] Next, a specific example of the abnormality factor determination will be described.
[0162] Fig. 22 is a schematic diagram showing a first example of changes in a measured value
and a predicted value in the use state of an energy storage system. Fig. 22 shows
temporal changes in the charge-discharge current, the voltage difference between required
storage cells among the plurality of energy storage cells forming the energy storage
system, and the temperature difference between the energy storage cells. Note that
the change illustrated in Fig. 22 is shown schematically and may differ from an actual
change. The length of the illustrated change period may be, for example, several hours,
12 hours, 24 hours, several days, and the like.
[0163] As shown in Fig. 22, each of the charge current and the discharge current varies
with a relatively small amplitude, and the measured cell current Ie is small. The
measured inter-cell voltage difference ΔV and the voltage difference ΔVec between
the measured and predicted values are each kept at small values.
[0164] As for the temperature difference, in the first half of the change period, the measured
inter-cell temperature difference ΔT has changed at a large value, and the temperature
difference ΔTec between the measured and predicted values has changed at a small value.
When the abnormality factor is determined at a time point ta, it is found that the
current flowing in the energy storage cell is small, and no heavy load is being applied
to the energy storage cell. Therefore, an influence inherent in the energy storage
cell is considered small. Although the measured temperature difference between the
energy storage cells is large, the difference from the predicted value (calculated
value) is small, so the temperature difference (e.g., environmental differences due
to differences in placement and installation conditions) can be determined to be within
an assumed range, and the energy storage system can be determined not to be abnormal.
[0165] As shown in Fig. 22, in the latter half of the change period, the state of the energy
storage system changes, and the measured inter-cell temperature difference ΔT changes
at a large value, and the temperature difference ΔTec between the measured and predicted
values also changes at a large value. When the abnormality factor is determined at
a time point tb, it is found that the current flowing through the energy storage cell
is small, and no heavy load is being applied to the energy storage cell. Therefore,
an influence inherent in the energy storage cell is considered small. Since the measured
temperature difference between the energy storage cells is large and the difference
from the predicted value (calculated value) is also large, there is a high possibility
that the environment of the energy storage cell exceeds the assumed range, and it
can be determined that the environment is abnormal.
[0166] Fig. 23 is a schematic diagram showing a second example of changes in the measured
value and the predicted value in the use state of the energy storage system. Fig.
23 shows temporal changes in the charge-discharge current, the voltage difference
between required storage cells among the plurality of energy storage cells forming
the energy storage system, and the temperature difference between the energy storage
cells. Note that the change illustrated in Fig. 23 is shown schematically and may
differ from an actual change. The length of the illustrated change period may be,
for example, several hours, 12 hours, 24 hours, several days, and the like.
[0167] As shown in Fig. 23, each of the charge current and the discharge current varies
with a relatively large amplitude, and the measured cell current Ie is large. The
measured inter-cell temperature difference ΔT changes at a large value in the first
half of the change period and changes at a small value in the second half of the change
period. The temperature difference ΔTec between the measured and predicted values
changes at a small value.
[0168] As for the voltage difference, in the first half of the change period, the measured
inter-cell voltage difference ΔV has changed at a large value, and the voltage difference
ΔVec between the measured and predicted values has changed at a small value. When
the abnormality factor is determined at a time point tc, it is found that the current
flowing through the energy storage cell is large and a heavy load is being applied
to the energy storage cell. Therefore, it is considered that there is a possibility
of an influence peculiar to the energy storage cell. Although the measured voltage
difference between the energy storage cells is large, the difference from the predicted
value (calculated value) is small, so it is highly likely that the voltage difference
is caused by the temperature difference between the energy storage cells or the deviation
of the SOC between the energy storage cells, and it can be determined that the voltage
difference is within the assumed range, and it can be determined that the energy storage
system is not abnormal.
[0169] As shown in Fig. 23, in the latter half of the change period, the state of the energy
storage system changes, and the measured inter-cell voltage difference ΔV changes
at a large value, and the voltage difference ΔVec between the measured and predicted
values changes at a large value. When the abnormality factor is determined at a time
point td, it is found that the current flowing through the energy storage cell may
be large and a heavy load is being applied to the energy storage cell. Therefore,
it is considered that there is a possibility of an influence peculiar to the energy
storage cell. Since the measured voltage difference between the energy storage cells
is large and the difference from the predicted value (calculated value) is also large,
it can be determined that the energy storage cell is abnormal.
[0170] As described above, the abnormality factor determination unit 233 can determine whether
the energy storage device is abnormal or the environment of the energy storage device
is abnormal. The abnormality of the energy storage device includes, for example, a
case where it is determined that the energy storage device deteriorates earlier than
assumed. Further, since the abnormality of the energy storage device and the abnormality
of the environment can be discriminated and determined, it is possible to prevent
erroneous determination of the abnormality of the energy storage device.
[0171] More specifically, the abnormality factor determination unit 233 can determine the
abnormality factor based on the measured value of the current acquired by the processing
unit 23, the measured voltage difference and the measured temperature difference calculated
by the first calculation unit 231, and the difference between the measured value and
the predicted value calculated by the second calculation unit 232. For example, when
the measured value of the current and the measured voltage difference between the
energy storage devices are large and the difference between the measured value and
the predicted value is also large, it can be determined that the one storage device
is abnormal. On the other hand, when the measured value of the current and the measured
voltage difference between the energy storage devices are large, but the difference
between the measured value and the predicted value is small, it can be determined
that the state is within assumption (not abnormal) due to, for example, the differences
in the arrangement and installation conditions between the energy storage devices
in the energy storage system, deviations in SOC between the energy storage devices,
or the like.
[0172] When the measured value of the current is small, the measured temperature difference
between the energy storage devices is large, and the difference between the measured
value and the predicted value is also large, it can be determined that the environment
is abnormal. On the other hand, when the measured value of the current is small and
the measured temperature difference between the energy storage devices is large, but
the difference between the measured value and the predicted value is small, it can
be determined that the state is within assumption (not abnormal) due to the differences
in the arrangement and installation conditions between the energy storage devices
in the energy storage system, or the like.
[0173] The abnormality factor determination unit 233 can be configured to include, for example,
machine learning using a rule-based model (finding a rule by using machine learning),
or can be configured to include a neural network model (learning apparatus). First,
the rule-based model will be described.
[0174] Fig. 24 is an explanatory diagram showing an example of the rule-based model for
determining an abnormality factor. In Fig. 24, four cases from No. 1 to No. 4 will
be described for convenience. In the case of NO. 1, the determination result of the
abnormality factor can be regarded as within assumption (no abnormality) when the
measured cell current Ie is less than the threshold, the measured inter-cell voltage
ΔV is less than a threshold, the measured inter-cell temperature ΔT is equal to or
more than a threshold, the voltage difference ΔVec between the measured and predicted
values is less than a threshold, and the temperature difference ΔTec between the measured
and predicted values is less than the threshold. In this case, the operation support
information of the energy storage system can be, for example, "Continue operation
in the present situation."
[0175] In the case of NO. 2, the determination result of the abnormality factor can be regarded
as an environmental abnormality when the measured cell current Ie is less than the
threshold, the measured inter-cell voltage ΔV is less than a threshold, the measured
inter-cell temperature ΔT is equal to or more than a threshold, the voltage difference
ΔVec between the measured and predicted values is equal to or more than a threshold,
and the temperature difference ΔTec between the measured and predicted values is less
than the threshold. In this case, the operation support information of the energy
storage system can be, for example, "Adjust air conditioning."
[0176] In the case of NO. 3, the determination result of the abnormality factor can be regarded
as within assumption (no abnormality) when the measured cell current Ie is equal to
or more than the threshold, the measured inter-cell voltage ΔV is equal to or more
than a threshold, the measured inter-cell temperature ΔT is equal to or more than
a threshold, the voltage difference ΔVec between the measured and predicted values
is less than a threshold, and the temperature difference ΔTec between the measured
and predicted values is less than the threshold. In this case, the operation support
information of the energy storage system can be, for example, "Continue operation
in the present situation."
[0177] In the case of NO. 4, the determination result of the abnormality factor can be regarded
as an abnormality of the energy storage device when the measured cell current Ie is
equal to or more than the threshold, the measured inter-cell voltage ΔV is equal to
or more than a threshold, the measured inter-cell temperature ΔT is less than a threshold,
the voltage difference ΔVec between the measured and predicted values is less than
a threshold, and the temperature difference ΔTec between the measured and predicted
values is equal to or more than the threshold. In this case, the operation support
information of the energy storage system can be, for example, "Reduce load or exchange
energy storage device."
[0178] Each threshold shown in Fig. 24 can be determined, for example, by machine learning.
[0179] The operation support information provision unit 234 has a function as the provision
unit and can provide the operation support information of the energy storage system
based on a result of the determination in the abnormality factor determination unit
233. As described above, for example, when it is determined that the energy storage
device is abnormal, the operation support information provision unit 234 can provide
information such as load reduction and replacement of the energy storage device. Further,
when it is determined that the environment is abnormal, the operation support information
provision unit 234 can provide information such as adjustment of air conditioning
(e.g., lowering the temperature, etc.), and can provide operation support information
for supporting the optimum operation of the energy storage system in accordance with
the abnormality factor.
[0180] Next, the neural network model will be described.
[0181] Fig. 25 is a schematic diagram showing an example of the configuration of a learning
model 233a. The learning model 233a is a neural network model including deep learning
and is made up of an input layer, an output layer, and a plurality of intermediate
layers. Although two intermediate layers are shown in Fig. 25 for convenience, the
number of intermediate layers is not limited to two but may be three or more.
[0182] In the input layer, the output layer, and the intermediate layer, there are one or
more nodes (neurons), and the node of each layer is coupled in one direction with
a desired weight to each of the nodes existing in the preceding and succeeding layers.
A vector having the same number of components as the number of nodes of an input layer
is provided as input data of the learning model 233a (input data for learning and
input data for determining an abnormality factor). The input data includes energy
storage device information (SOC, full charge capacity, SOC-OCV (open circuit voltage)
curve, internal resistance, etc.), a measured cell current, a measured inter-cell
voltage, a voltage difference between measured and predicted values, a temperature
difference between measured and predicted values, and the like. The output data includes
abnormality factors (abnormality of the energy storage device, environmental abnormality,
being within an assumed range and no abnormality, etc.).
[0183] The output data can be data in a vector format having components of the same size
as the number of nodes (size of the output layer) of the output layer. For example,
the output node can output probabilities of "abnormality of the energy storage device,"
"environmental abnormality," "the state of the energy storage device is within assumption,"
and "the state of the environment is within assumption," respectively.
[0184] The learning model 233a can be configured, for example, by combining hardware such
as a CPU (e.g., multiple processors mounted with a plurality of processor cores, etc.),
a graphics processing unit (GPU), a digital signal processor (DSP), a field-programmable
gate array (FPGA), and the like.
[0185] The learning model 233a has learned based on learning data having, as input data,
the measured value of the current of the plurality of energy storage devices, the
measured voltage difference and the measured temperature difference between required
storage devices, and the difference between the measured value and the predicted value
with respect to each of the voltage and the temperature of one of the required storage
devices, the leaning data having the abnormality factor as output data.
[0186] The learning model 233a has learned so as to output the abnormality of the one storage
device when, for example, the measured current value and the measured voltage difference
between the energy storage devices are large and the difference between the measured
value and the predicted value is also large. The learning model 233a has learned so
as to output a state within assumption (not abnormal) when the measured value of the
current and the measured voltage difference between the energy storage devices are
large and the difference between the measured value and the predicted value is small.
[0187] The learning model 233a has learned so as to output that the environment is abnormal
when the measured value of the current is small, the measured temperature difference
between the energy storage devices is large, and the difference between the measured
value and the predicted value is also large. The learning model 233a has learned so
as to output that the state is within assumption (not abnormal) when the measured
value of the current is small, the measured temperature difference between the energy
storage devices is large, and the difference between the measured value and the predicted
value is small.
[0188] The abnormality factor determination unit 233 can input the measured value of the
current acquired by the processing unit 23, the measured voltage difference and the
measured temperature difference calculated by the first calculation unit 231, and
the difference between the measured value and the predicted value calculated by the
second calculation unit 232, into the learning model 233a to determine the abnormality
factor. It is thereby possible to determine an abnormality factor (e.g., the abnormality
of the energy storage device (degradation earlier than assumed, or the like) or the
abnormality of the environment of the energy storage device). Further, since the abnormality
of the energy storage device and the abnormality of the environment can be discriminated
and determined, it is possible to prevent erroneous determination of the abnormality
of the energy storage device.
[0189] Fig. 26 is a flowchart showing an example of the processing procedure of the server
apparatus 2 according to the second embodiment. For convenience, the main part of
the processing will be described as the processing unit 23. The processing unit 23
acquires measured values of the currents, voltages, and temperatures of the plurality
of energy storage devices (S31) and acquires predicted values of the voltages and
temperatures of the plurality of energy storage devices (S32).
[0190] The processing unit 23 calculates the measured inter-cell voltage and the measured
inter-cell temperature (S33) and calculates the difference between the measured value
and the predicted value with respect to the voltage and the temperature (S34). The
processing unit 23 determines an abnormality factor (S35) and determines whether or
not the cause is within assumption (S36).
[0191] When it is not within assumption (NO in S36), the processing unit 23 outputs operation
support information corresponding to the abnormality factor (S37) and performs processing
of S38 to be described later. When it is within assumption (YES in S36), the processing
unit 23 maintains the operation in the present situation (S39) and determines whether
or not to end the processing (S38). When the processing is not to be ended (NO in
S38), the processing unit 23 continues the processing from S31, and when the processing
is to be ended (YES in S38), the processing is ended.
[0192] The control unit 20 and the processing unit 23 of the present embodiment can also
be achieved using a general-purpose computer provided with a CPU (processor), a GPU,
a RAM (memory), and the like. That is, the control unit 20 and the processing unit
23 can be achieved on a computer by loading a computer program that determines the
procedure of each processing, as shown in Figs. 18, 19 and 26, into the RAM (memory)
provided in the computer and executing the computer program with the CPU (processor).
The computer program may be recorded on a recording medium and distributed. The learning
model 26 caused to learn by the server apparatus 2, the computer program based on
the learning model, and the data for learning may be distributed to and installed
into the target apparatuses P, U, D, M for remote monitoring, the terminal apparatus
(measurement monitor), the communication device 1, or the client apparatus 3 via the
network N and the communication device 1. In this case, in the target apparatuses
P, U, D, M, the terminal apparatus (measurement monitor), the communication device
1, or the client apparatus 3, the learning of the learning model 26 and the degradation
determination by the learning-completed learning model 26 can be performed.
[0193] In the embodiment described above, the learning model 26 may be, for example, a recurrent
neural network (regression neural networks: RNN). In this case, the intermediate layer
of the previous time may be learned together with the input of the next time.
[0194] Embodiments are exemplary in all respects and are not restrictive. The scope of the
present invention is defined by the claims and includes meanings equivalent to the
claims and all modifications within the claims.
DESCRIPTION OF REFERENCE SIGNS
[0195]
- 2:
- server apparatus
- 20:
- control unit
- 21:
- communications unit
- 22:
- storage unit
- 23:
- processing unit
- 231:
- first calculation unit
- 232:
- second calculation unit
- 233:
- abnormality factor determination unit
- 234:
- operation support information provision unit
- 24:
- predicted data generation unit
- 25:
- learning data generation unit
- 26, 233a:
- Learning model
- 27:
- learning processing unit
- 28:
- input data generation unit
1. An abnormality factor determination apparatus for determining presence or absence
of an abnormality factor relating to an energy storage system that includes a plurality
of energy storage devices, the apparatus comprising:
a measured value acquisition unit that acquires measured values, the measured values
including electric values and temperature values of the plurality of energy storage
devices;
a predicted value acquisition unit that acquires predicted values, the predicted values
including electric values and temperature values of the plurality of energy storage
devices; and
a determination unit that determines presence or absence of an abnormality factor
relating to the energy storage system based on the measured values acquired by the
measured value acquisition unit and the predicted values acquired by the predicted
value acquisition unit.
2. The abnormality factor determination apparatus according to claim 1, comprising a
provision unit that provides operation support information of the energy storage system
based on a result of the determination in the determination unit.
3. The abnormality factor determination apparatus according to claim 1 or 2, comprising:
a first calculation unit that calculates a measured voltage difference and a measured
temperature difference between certain energy storage devices based on the measured
values acquired by the measured value acquisition unit; and
a second calculation unit that calculates a difference between a measured value and
a predicted value with respect to each of a voltage and a temperature of one of the
certain energy storage devices based on the measured values acquired by a measured
value acquisition unit and the predicted values acquired by the predicted value acquisition
unit,
wherein the determination unit determines the presence or absence of the abnormality
factor based on the measured current value acquired by the measured value acquisition
unit, the measured voltage difference and the measured temperature difference calculated
by the first calculation unit, and the difference between the measured value and the
predicted value calculated by the second calculation unit.
4. The abnormality factor determination apparatus according to any one of claims 1 to
3, wherein the determination unit determines whether the abnormality factor is an
abnormality of the energy storage device or an abnormality of an environment of the
energy storage device.
5. The abnormality factor determination apparatus according to claim 3, comprising a
learning apparatus caused to learn based on learning data having, as input data, the
measured current values of the plurality of energy storage devices, the measured voltage
difference and the measured temperature difference between the certain energy storage
devices, and the difference between the measured value and the predicted value with
respect to each of the voltage and the temperature of one of the certain energy storage
devices, the learning data having the abnormality factor as output data,
wherein the determination unit inputs to the learning unit the measured current value
acquired by the measured value acquisition unit, the measured voltage difference and
the measured temperature difference calculated by the first calculation unit, and
the difference between the measured value and the predicted value calculated by the
second calculation unit, and determines presence or absence of an abnormality factor.
6. A degradation determination apparatus for determining degradation of an energy storage
device, the apparatus comprising:
a measured data acquisition unit that acquires measured time-series data, the measured
time-series data including a measured electric value and a measured temperature value
of the energy storage device;
a predicted data acquisition unit that acquires predicted time-series data, the predicted
time-series data including a predicted electric value and a predicted temperature
value of the energy storage device; and
a learning processing unit that causes a learning model to learn based on learning
data having the measured time-series data and the predicted time-series data as input
data and having determination of degradation of the energy storage device as output
data.
7. The degradation determination apparatus according to claim 6, wherein the learning
processing unit causes the learning model to learn based on learning data having,
as input data, respective pieces of time-series data of: a difference or a ratio between
the measured electric value and the predicted electric value; and a difference or
a ratio between the measured temperature value and the predicted temperature value.
8. The degradation determination apparatus according to claim 6 or 7, wherein
the measured data acquisition unit acquires measured time-series data including a
measured voltage value of the energy storage device,
the predicted data acquisition unit acquires predicted time-series data including
a predicted voltage value of the energy storage device, and
the learning processing unit causes the learning model to learn based on learning
data having the measured time-series data that includes the measured voltage value
and the predicted time-series data that includes the predicted voltage value as input
data.
9. The degradation determination apparatus according to claim 8, wherein
the measured data acquisition unit acquires measured time-series data including a
measured current value of the energy storage device,
the predicted data acquisition unit acquires predicted time-series data including
a predicted current value of the energy storage device, and
the learning processing unit causes the learning model to learn based on learning
data having the measured time-series data that includes the measured current value
and the predicted time-series data that includes the predicted current value as input
data.
10. The degradation determination apparatus according to any one of claims 6 to 9, wherein
the measured data acquisition unit acquires measured time-series data including a
difference or a ratio between a measured electric value of each of the plurality of
energy storage cells forming an energy storage module and an average value of the
measured electric values of the plurality of energy storage cells, and
the learning processing unit causes the learning model to learn based on learning
data having measured time-series data that includes the difference or the ratio as
input data.
11. The degradation determination apparatus according to any one of claims 6 to 10, wherein
the predicted data acquisition unit acquires predicted time-series data including
a difference or a ratio between a predicted electric value of each of the plurality
of energy storage cells forming an energy storage module and an average value of the
predicted electric values of the plurality of energy storage cells, and
the learning processing unit causes the learning model to learn based on learning
data having predicted time-series data that includes the difference or the ratio as
input data.
12. The degradation determination apparatus according to any one of claims 6 to 11, wherein
the predicted data acquisition unit acquires predicted time-series data that includes
a difference or a ratio between a predicted temperature value of each of the plurality
of energy storage cells forming an energy storage module and an average value of the
predicted temperature values of the plurality of energy storage cells, and
the learning processing unit causes the learning model to learn based on learning
data having predicted time-series data that includes the difference or the ratio as
input data.
13. The degradation determination apparatus according to any one of claims 6 to 12, wherein
the measured data acquisition unit acquires measured time-series data including a
measured pressure value of the energy storage device,
the predicted data acquisition unit acquires predicted time-series data including
a predicted pressure value of the energy storage device, and
the learning processing unit causes the learning model to learn based on learning
data having time-series data that includes a difference or a ratio between the measured
pressure value and the predicted pressure value as input data.
14. The degradation determination apparatus according to any one of claims 6 to 13, wherein
the learning processing unit causes the learning model to learn based on learning
data having presence or absence of an environmental abnormality relating to the energy
storage device as output data.
15. The degradation determination apparatus according any one of claims 6 to 14, wherein
deterioration of the energy storage device is determined using a learning-completed
learning model caused to learn by the learning processing unit.
16. A degradation determination apparatus for determining degradation of an energy storage
device, the apparatus comprising:
a measured data acquisition unit that acquires measured time-series data, the measured
time-series data including a measured electric value and a measured temperature value
of the energy storage device;
a predicted data acquisition unit that acquires predicted time-series data, the predicted
time-series data including a predicted electric value and a predicted temperature
value of the energy storage device; and
a learning-completed learning model that uses the measured time-series data and the
predicted time-series data as input data to output determination of degradation of
the energy storage device.
17. A computer program for causing a computer to determine presence or absence of an abnormality
factor relating to an energy storage system including a plurality of energy storage
devices, the program causing the computer to perform
processing of acquiring measured values, measured values including electric values
and temperature values of the plurality of energy storage devices,
processing of acquiring predicted values, the predicted values including electric
values and temperature values of the plurality of energy storage devices, and
processing of determining presence or absence of an abnormality factor relating to
the energy storage system based on the acquired measured values and the acquired predicted
values.
18. A computer program for causing a computer to determine degradation of an energy storage
device, the program causing the computer to perform
processing of acquiring measured time-series data, the measured time-series data including
a measured electric value and a measured temperature value of the energy storage device,
processing of acquiring predicted time-series data, the predicted time-series data
including a predicted electric value and a predicted temperature value of the energy
storage device, and
processing of causing a learning model to learn based on learning data having the
measured time-series data and the predicted time-series data as input data and having
determination of degradation of the energy storage device as output data.
19. A computer program for causing a computer to determine degradation of an energy storage
device, the program causing the computer to perform
processing of acquiring measured time-series data, the measured time-series data including
a measured electric value and a measured temperature value of the energy storage device,
processing of acquiring predicted time-series data, the predicted time-series data
including a predicted electric value and a predicted temperature value of the energy
storage device, and
processing of inputting the measured time-series data and the predicted time-series
data into a learning-completed learning model to determine degradation of the energy
storage device.
20. An abnormality factor determining method for determining presence or absence of an
abnormality factor relating to an energy storage system that includes a plurality
of energy storage devices, the method comprising:
acquiring measured values, the measured values including electric values and temperature
values of the plurality of energy storage devices;
acquiring predicted values, the predicted values including electric values and temperature
values of the plurality of energy storage devices; and
determining presence or absence of an abnormality factor relating to the energy storage
system based on the acquired measured values and the acquired predicted values.
21. A degradation determining method for determining degradation of an energy storage
device, the method comprising:
acquiring measured time-series data, the measured time-series data including a measured
electric value and a measured temperature value of the energy storage device;
acquiring predicted time-series data, the predicted time-series data including a predicted
electric value and a predicted temperature value of the energy storage device; and
causing a learning model to learn based on learning data having the measured time-series
data and the predicted time-series data as input data and determination of degradation
of the energy storage device as output data.
22. A degradation determining method for determining degradation of an energy storage
device, the method comprising:
acquiring measured time-series data, the measured time-series data including a measured
electric value and a measured temperature value of the energy storage device;
acquiring predicted time-series data, the predicted time-series data including a predicted
electric value and a predicted temperature value of the energy storage device; and
inputting the measured time-series data and the predicted time-series data into a
learning-completed learning model to determine degradation of the energy storage device.